The invention relates generally to concrete forming apparatus and, more specifically, to apparatus for holding a partial sheet of insulation at a preselected position inside a concrete form.
Concrete forming systems are in wide use in forming concrete structures. One application is in the formation of insulated concrete walls. A common system erects a concrete form on footings wherein a pair of form panels are separated by a gap into which concrete is placed to form a wall. Insulation is often placed in the gap prior to the addition of the concrete so that the wall has improved thermal properties as taught in U.S. Pat. Nos. 4,329,821 and 4,393,635 (both to Long et al.), both of which are herein incorporated by reference. A plurality of spacing elements, usually forming a part of the insulation, maintains the insulation within the gap between the form panels so that a layer of concrete is formed on either side of the insulation. The most common insulation used is lightweight, rigid foam sheets that, most typically, extend the fall height of the concrete form panels. Currently these insulation sheets sit on the same bottom surface that the forms sit on to support the insulation height and to prevent the insulation from being forced downward by the force of placing the plastic concrete to a point that would place the top edge of the foam below the top edge of the form. Additionally, these insulation sheets are buoyant and float upwardly as the plastic concrete is placed in the gap and therefore need to be held down by straps or similar structure placed on top of the form panels. There are times, however, where it is desired to use a foam sheet that is not the full height of the concrete form.
If a partial sheet of insulation is desired, the conventional method of placing the insulation and pouring the concrete requires placement of the concrete up to a certain height and then concrete pouring is interrupted so that the partial height insulation sheet can be placed in position and concrete pouring is resumed. But with this method, the rigid foam insulation floats up as additional concrete is placed adjacent to the insulation due to hydrostatic pressure. The other short coming of this method is that it is very difficult to achieve the correct height for the lower portion of the concrete in which no insulation is present. The present invention overcomes these shortcomings by suspending the less than full height rigid insulation sheets in the concrete formwork with the use of tie sleeves.